Fluid connection

ABSTRACT

A fluid connection comprised of a first fitting having a body with a first end and a second end. A passage extends through the body from the first end to the second end. A bracket is mounted to the second end of the body. The bracket defines a space adjacent the second end. A mounting element is provided for mounting the first end of the body to a fluid inlet line. A piston is movable within the passage. The piston has an outer surface, an inlet side facing the first end of the body and an outlet side facing the second end of the body. An aperture through the piston fluidly connects the inlet side of the piston to the outlet side of the piston. A second fitting, having a fluid opening therethrough, is dimensioned to be slidably received within the space adjacent the second end of the fitting. The piston is movable into engagement with the second fitting with the aperture in the piston communicating with the fluid opening in the second fitting.

RELATED APPLICATIONS

The present application is a continuation-in-part (CIP) application ofU.S. application Ser. No. 10/857,338, entitled “Fluid Connection,” andfiled on May 28, 2004, now U.S. Pat. No. 7,314,238, which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to connection fittings for fluid conduits,and more particularly to a quick connect/disconnect connection for usein a washer for microbially decontaminating items.

BACKGROUND OF THE INVENTION

Medical instruments and equipment that are exposed to biologicalcontaminants require microbial decontamination between uses. It is knowto microbially decontaminate medical instruments and equipment inwashers by exposing the medical instruments or equipment to a liquidmicrobial decontaminating solution. Known washing systems for microbialdecontamination of medical instruments and equipment typically includebaskets or racks that retain the various equipment or instruments to becleaned. The baskets or racks are usually movable within the washer tofacilitate loading and unloading of the washer. It is also known to havespray heads mounted to the movable racks or baskets to direct themicrobial decontaminating solution over the instruments therein. Sometype of fluid connection is therefore required between a stationaryfluid inlet line on the washer and a movable fluid line on the rack orbasket, or between the stationary fluid inlet line on the washer andsome accessory used within the washer.

The present invention provides a fluid connection that is quick and easyto connect and disconnect in a washer for microbially decontaminatingmedical, surgical or veterinary instruments or equipment.

SUMMARY OF THE INVENTION

In accordance with a preferred embodiment of the present invention,there is provided a quick connect/disconnect connection for a fluid linecomprised of a body having a first end and a second end. The first endof the body is connectable to a stationary fluid inlet line. A passageextends through the body, and a piston is movable within the passage.The piston has an outer surface, an inlet side and an outlet side. Theinlet side has a surface oriented toward the fluid inlet to be exposedto pressurized fluid from the fluid inlet. An aperture through thepiston fluidly connects the inlet side of the piston to the outlet sideof the piston. A bracket element is mounted to the second end of thebody and defines a space adjacent the second end. A movable fitting,having a fluid opening connectable to a fluid supply line, isdimensioned to be received within the space adjacent the body. Thepiston is movable into engagement with the fitting with the aperture inthe piston communicating with the fluid opening in the fitting when theinlet side of the piston is exposed to fluid pressure in the inlet line.

In accordance with the present invention, there is provided a fluidconnection comprised of a first fitting having a body with a first endand a second end. A passage extends through the body from the first endto the second end. A bracket is mounted to the second end of the body.The bracket defines a space adjacent the second end. A mounting elementis provided for mounting the first end of the body to a fluid inletline. A piston is movable within the passage. The piston has an outersurface, an inlet side facing the first end of the body and an outletside facing the second end of the body. An aperture through the pistonfluidly connects the inlet side of the piston to the outlet side of thepiston. A second fitting, having a fluid opening therethrough, isdimensioned to be slidably received within the space adjacent the secondend of the fitting. The piston is movable into engagement with thesecond fitting with the aperture in the piston communicating with thefluid opening in the second fitting.

One advantage of the present invention is a fluid connection that isquickly and easily connected and disconnected.

Another advantage of the present invention is a fluid connection asdescribed above for use in a washer for microbially cleaning anddecontaminating items.

These and other objects will become apparent from the followingdescription of a preferred embodiment taken together with theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangement ofparts, a preferred embodiment of which will be described in detail inthe specification and illustrated in the accompanying drawings whichform a part hereof, and wherein:

FIG. 1 is a perspective view of the fluid connection for connectingfluid conduit in a washer for microbially decontaminating items,illustrating a preferred embodiment of the present invention;

FIG. 2 is a perspective view showing first fitting attached to astationary fluid inlet and second fitting attached to a removableaccessory;

FIG. 3 is a partially sectioned, elevational view of the fluidconnection shown in FIG. 1;

FIG. 4 is a section view taken along lines 4-4 of FIG. 3;

FIG. 5 is a perspective view of a piston used in the fluid connectionshown in FIGS. 1-4;

FIG. 6 is a partially sectioned, exploded view of a piston assemblyillustrating an alternative embodiment of the present invention;

FIG. 7 is a partially sectioned, elevational view of a fluid connectionhaving the piston assembly shown in FIG. 6 disposed therein; and

FIG. 8 is a sectioned, elevational view of the fluid connection shown inFIG. 7 showing the piston assembly engaging a misaligned second fitting.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings wherein the showings are for the purposeof illustrating a preferred embodiment of the invention only, and notfor the purpose of limiting same, FIG. 1 shows a fluid connection 10,illustrating a preferred embodiment of the present invention. Fluidconnection 10 is basically comprised of a first, stationary fitting 30for attachment to a stationary fluid inlet line or conduit 12 and asecond, accessory fitting 100 for attachment to a fluid supply line orconduit 14, as best seen in FIG. 2, wherein fittings 30, 100 are shownspaced-apart from each other. Stationary fluid inlet line 12 has a fluidopening 12 a extending therethrough. Fluid supply line 14 has a fluidopening 14 a extending therethrough. As used herein, the term“stationary fitting” refers to a fitting that is adapted to be connectedto a stationary fluid inlet line, such as, by way of example and notlimitation, a stationary water inlet pipe on a microbial deactivationwasher (not shown). Such inlet line typically extends into the interiorcavity of a washer for connection to an accessory, such as spray headson a rack or basket (not shown), used in the washer. As used herein, theterm “movable fitting” refers to a fitting adapted to be attached to afluid supply conduit that is movable relative to a stationary fluidinlet line, such as, by way of example and not limitation, a fluidsupply line to a spray on a movable basket used in the washer, or to aninstrument or piece of equipment to be washed in a movable basket withinthe washer. In this respect, the accessory above may be a spray head oran instrument on a rack or basket that is movable within the washer.

In the embodiment shown, first, stationary fitting 30 includes a pistonbody 32, best seen in FIG. 3. Piston body 32 is cylindrical in shape andincludes an outwardly extending annular flange 34 at one end and anoutwardly extending boss or mount 36 at the other end.

Flange 34 has a planar surface 43 a dimensioned to mate with a planarsurface 16 a on a flange element 16 of stationary fluid inlet line 12.An annular seal 42 is disposed between flange 34 on piston body 32 andflange 16 on stationary fluid inlet line 12 to form a fluid sealtherebetween. Flanges 34 and flange element 16 are held together by aconventional collar clamp 44 comprised of clamp sections 44 a, 44 b,that are hinged together at one end (not shown) and have slotted tabs 44c, 44 d at the other end. A thumbnut 52 and a thread rod 54 attached toslotted tab 44 d are used to secure collar section 44 a, 44 b ontoflanges 34 on piston body 32 and flange element 16 on stationary fluidinlet line 12. As best seen in FIG. 3, flange 34 and flange element 16have beveled edges to matingly engage tapered inner surfaces along theinner edge of collar clamp sections 44 a, 44 b. In this respect,tightening collar clamp 44 forces flange 34 and flange element 16towards each other thereby forming a fluid-tight seal between stationaryfluid inlet line 16 and piston body 32, in a manner conventionallyknown.

Annular mount 36 on piston body 32 has a generally C-shaped bracket 53secured thereto. Bracket 53 is preferably formed from a metallic sheetmaterial that is bent into a generally C-shaped configuration. Bracket53 has a planar base 55 and sides 56, 58 that are generally L-shaped.Sides 56, 58 have inwardly turned ends 56 a, 58 a. A generallyrectangular slot or space 62 is formed between planar base 55 and ends56 a, 58 a of C-shaped bracket 53 and the inwardly turned ends.

Piston body 32 defines a cylindrical inner cavity 72 that communicateswith opening 12 a in stationary fluid inlet line 12, and that extendsthrough C-shaped bracket 53 to communicate with slot 62 defined byC-shaped bracket 53. An inwardly extending lip 74 is formed at one endof piston body 32, as best seen in FIG. 3. Lip 74 is formed on the endof piston body 32 where C-shaped bracket 53 is connected to piston body32.

Piston cavity 72 is dimensioned to receive a piston 82, best seen inFIG. 5. Piston 82 is generally cylindrical in shape. Piston 82 may be asolid cylindrical plug, but in the embodiment shown, piston 82 isgenerally C-shaped. In this respect, piston 82 includes a bottom wall 84and an annular, cylindrical side wall 86 extending to one side of bottomwall 84. A plurality of spaced-apart apertures 88 are formed in bottomwall 84, as best seen in FIG. 5. Apertures 88 are dimensioned such thatthe total cross-sectional area of all apertures 88 is less than thecross-sectional area of opening 12 a of stationary fluid inlet line 12.In the illustrated embodiment, an annular slot 92 is formed in the endface of bottom wall 84 along the periphery thereof. In an alternativeembodiment, annular slot 92 may be omitted. The free end of side wall 86is tapered to form a conical-shaped end 94, as best seen in FIG. 3. Byway of example, and not limitation, piston 82 may be formed of Teflon®or stainless steel.

Referring now to FIG. 2, accessory fitting 100 is best seen. Accessoryfitting 100 is a tubular member comprised of a cylindrical body 112having an outwardly extending flange 114 at one end thereof. Body 112has a cylindrical opening 122 extending therethrough. Flange 114 has anouter edge 114 a that is tapered, and a planar end surface 114 b.Second, accessory fitting 100 is dimensioned to be attached to fluidsupply line 14 by a conventional hose or tube fitting 132, asillustrated in the drawings. Accessory fitting 100 is dimensioned to beslidably received within rectangular space 62 defined by C-shapedbracket 53 of first, stationary fitting 30.

Referring now to the operation of fluid connection 10, first, stationaryfitting 30 is attached to stationary fluid inlet line 12 by means ofcollar clamp 44. Second, accessory fitting 100 is positioned adjacentfirst, stationary fitting 30 by sliding flange 114 on cylindrical body112 into space or slot 62 defined by C-shaped bracket 53. Second,accessory fitting 100 is positioned such that cylindrical opening 122 isaligned with piston cavity 72 in piston body 32. In this respect,cylindrical opening 122 of second, accessory fitting 100 is basically inaxial alignment with the axis of cylindrical piston 82. During theoperation of the washer, pressurized fluid flows through stationaryfluid inlet line 12 into cavity 72 of piston body 32. Since apertures 88and piston 82 in total define a smaller, cross-sectional area than thecross-sectional area of opening 12 a of stationary fluid inlet line 12,a pressure build up will occur within cavity 72 in piston body 32. Thepressure on the face of bottom wall 84 of piston 82 forces piston 82 ina direction towards surface 114 b of flange 114. In this respect,conical end 94 of piston 82 is forced against surface 114 b of flange114 forming a fluid connection therewith. Fluid flows through apertures88 into cylindrical opening 122 of cylindrical body 112 of second,accessory fitting 100. From there, pressurized fluid flows throughopening 14 a of fluid supply line 14 to an accessory device within thewasher. Following completion of a washing cycle, the flow of pressurizedfluid through stationary fluid inlet line 12 is discontinued. As aresult, pressure no longer exists against bottom wall 84 of piston 82 toforce piston 82 against surface 114 a on flange 114 of second, accessoryfitting 100. As a result, second, accessory fitting 100 may bedisconnected from first, stationary fitting 30 by sliding fitting 100out of slot 62 defined by C-shaped bracket 53. The present inventionthus provides a quick connect and quick disconnect fluid connectionwherein fluid pressure during operation effectively forms a fluidconnection between first, stationary fitting 30 and second, accessoryfitting 100 by forcing piston 82 into engagement with surface 114 b ofsecond, accessory fitting 100.

Referring now to FIGS. 6-8, an alternative embodiment of the presentinvention is shown. In FIGS. 6-8, parts that are similar to thosedescribed above in FIGS. 1-5 are given identical numbers. FIG. 6 shows apiston assembly 180. Piston assembly 180 is basically comprised of apiston 182 and a seal element 202.

Piston 182 is generally cylindrical in shape with an outer surface 184,a flat end 186 and a conical-shaped end 188. A cylindrical bore 192extends axially through piston 182. By way of example, and notlimitation, piston 182 may be formed of Teflon® or stainless steel. Anannular groove 194 is formed in outer surface 184 of piston 182. In theembodiment shown, annular groove 194 has a stepped bottom 195 defined bya first bottom surface 195 a and a second bottom surface 195 b. Bottomsurface 195 b defines an annular recess 196 within groove 194. At leastone hole 198 extends radially through a side wall of piston 182 suchthat annular groove 194 communicates with cylindrical bore 192. In theembodiment shown, a plurality of holes 198 extend radially through theside wall of piston 182 from first bottom surface 195 a of annulargroove 194 to bore 192.

Seal element 202 is generally a ring-shaped element formed of a softelastomeric material. Seal element 202 is dimensioned to be receivedinto annular groove 194 of piston 182. In the embodiment shown, sealelement 202 has a J-shaped cross-section with a base portion 202 a, anouter leg portion 202 b and an inner leg portion 202 c. Seal element 202is dimensioned to be received into annular groove 194 wherein inner leg202 c is disposed in annular recess 196 and outer leg portion 202 b isdisposed within annular groove 194. In this respect, outer leg portion202 b, base portion 202 a, inner leg portion 202 c, first bottom surface195 a and a side wall of annular groove 194 define a cavity 204 betweenseal element 202 and outer surface 184 of piston 182.

Piston assembly 180 is dimensioned to be disposed in cavity 72 of pistonbody 32. Piston 182 of piston assembly 180 and cavity 72 are dimensionedto form a gap 206 between outer surface 184 of piston 182 and cavity 72.Gap 206 is dimensioned to allow piston assembly 180 to be cantedslightly within cavity 72 such that piston assembly 180 and cavity 72are axially misaligned, as shown in FIG. 8. Gap 206 is dimensioned suchthat piston assembly 180 slides axially within cavity 72 whether pistonassembly 180 and cavity 72 are axially aligned, as shown in FIG. 7, oraxially misaligned, as shown in FIG. 8. According to one embodiment ofthe present invention, gap 206 is about 1/32 of an inch (about 0.079cm).

Referring now to the operation of the alternative embodiment of fluidconnection 10, first, stationary fitting 30 is attached to stationaryfluid inlet line 12 by means of collar clamp 44. Second, accessoryfitting 100 is positioned adjacent first, stationary fitting 30 bysliding flange 114 on cylindrical body 112 into space or slot 62 definedby C-shaped bracket 53. Second, accessory fitting 100 is positioned suchthat cylindrical opening 122 is aligned with piston cavity 72 in pistonbody 32. In this respect, cylindrical opening 122 of second, accessoryfitting 100 is basically in axial alignment with the axis of cylindricalpiston 182. During the operation of the washer, pressurized fluid flowsthrough stationary fluid inlet line 12 into cavity 72 of piston body 32.The fluid impacts the face of flat end 186 of piston 182 forcing piston182 in a direction towards surface 114 b of flange 114. In this respect,conical end 188 of piston 182 is forced against surface 114 b of flange114 forming a fluid connection therewith. As fluid continues to flowthrough cavity 72, a pressure build up will occur within cavity 72 inpiston body 32. The pressure in cavity 72 forces fluid to flow throughholes 198 into cavity 204 between seal element 202 and side wall 184 ofpiston 182. The pressure in cavity 204 causes outer leg portion 202 b ofseal element 202 to expand such that a fluid-tight radial seal is formedbetween piston 182 and piston body 32, as best seen in FIG. 7.

In accordance with one aspect of the present invention, piston assembly180 creates a fluid connection with flange 114 and piston body 32 in theevent of axial misalignment between first, stationary fitting 30 andsecond, accessory fitting 100. As stated above, piston assembly 180 andcavity 72 are dimensioned such that piston assembly 180 may be cantedwithin cavity 72 such that piston assembly 180 and cavity 72 are axiallymisaligned. As shown in FIG. 8, piston assembly 180 is canted slightlywithin cavity 72 such that conical end 188 of piston 182 is parallel tosurface 114 b of flange 114 and conical end 188 is forced againstsurface 114 b forming a fluid connection therewith. In addition, sealelement 202 expands such that a fluid-tight radial seal is formedbetween piston 182 and piston body 32. The present invention thusprovides fluid-tight seals between piston 182 and flange 114 and betweenpiston 182 and cavity 72, whether first, stationary fitting 30 andsecond, accessory fitting 100 are axially aligned or axially misaligned.

Fluid flows through bore 192 into cylindrical opening 122 of cylindricalbody 112 of second, accessory fitting 100. From there, pressurized fluidflows through opening 14 a of fluid supply line 14 to an accessorydevice within the washer. Following completion of a washing cycle, theflow of pressurized fluid through stationary fluid inlet line 12 isdiscontinued. As a result, pressure no longer exists against end wall186 of piston 182 to force piston 182 against surface 114 b on flange114 of second, accessory fitting 100. As a result, second, accessoryfitting 100 may be disconnected from first, stationary fitting 30 bysliding fitting 100 out of slot 62 defined by C-shaped bracket 53. Thepresent invention thus provides a quick connect and quick disconnectfluid connection wherein the flow of fluid during operation effectivelyforms a fluid connection between first, stationary fitting 30 andsecond, accessory fitting 100 by forcing piston 182 into engagement withsurface 114 b of second, accessory fitting 100. The fluid pressureduring operation forms a fluid-tight connection between piston body 32and piston 182 by forcing pressurized fluid into cavity 204 between sealelement 202 and piston 182. The fluid pressure in cavity 204 causes sealelement 202 to expand thereby creating a fluid-tight radial seal betweenpiston 182 and piston body 32.

The foregoing description is a specific embodiment of the presentinvention. It should be appreciated that this embodiment is describedfor purposes of illustration only, and that numerous alterations andmodifications may be practiced by those skilled in the art withoutdeparting from the spirit and scope of the invention. It is intendedthat all such modifications and alterations be included insofar as theycome within the scope of the invention as claimed or the equivalentsthereof.

1. A quick connect/disconnect connection for a fluid line, comprised of:a body having a first end and a second end, said first end beingconnectable to a stationary fluid inlet line; a passage extendingthrough said body; a piston movable within said passage, said pistonhaving an outer surface, an inlet side and an outlet side, said inletside having a surface oriented toward said fluid inlet line to beexposed to pressurized fluid from said fluid inlet line; an aperturethrough said piston fluidly connecting said inlet side of said piston tosaid outlet side of said piston; bracket means mounted to said secondend of said body defining a space adjacent said second end; and amovable fitting having a fluid opening connectable to a fluid supplyline, said fitting dimensioned to be received within said space adjacentsaid body, wherein said piston is movable into engagement with saidfitting with said aperture in said piston communicating with said fluidopening in said fitting when said inlet side of said piston is exposedto fluid pressure in said inlet line.
 2. A quick connect/disconnectconnection as defined in claim 1, wherein said body and said passagetherein are cylindrical in shape.
 3. A quick connect/disconnectconnection as defined in claim 2, wherein said piston is generallycup-shaped and has a bottom wall defining said surface and an annular,cylindrical side wall extending therefrom.
 4. A quick connect/disconnectconnection as defined in claim 3, wherein said first end of said bodyincludes a flange for mounting said body to said fluid inlet line.
 5. Aquick connect/disconnect connection as defined in claim 4, wherein saidfirst end of said body is attachable to said fluid inlet line by acollar clamp.
 6. A quick connect/disconnect connection as defined inclaim 1, wherein said piston forms a seal against a surface on saidfitting.
 7. A quick connect/disconnect connection as defined in claim 6,wherein said surface on said fitting is a planar surface.
 8. A quickconnect/disconnect connection as defined in claim 1, wherein saidbracket means is a generally C-shaped plate defining a generallyrectangular space, and said fitting is a flanged component dimensionedto be slidably received in said rectangular space.
 9. A quickconnect/disconnect connection as defined in claim 8, wherein saidfitting includes a cylindrical body having an annular outwardlyextending flange at one end of said cylindrical body, said flange havinga planar end surface.
 10. A quick connect/disconnect connection asdefined in claim 1, wherein said aperture in said piston is dimensionedsuch that the total cross-sectional area of said aperture is less thanthe cross-sectional area of said stationary fluid inlet line.
 11. Afluid connection as defined in claim 1, further comprising: an annulargroove formed in said outer surface of said piston; at least one holeextending radially through said piston, said hole fluidly connectingsaid aperture in said piston to said annular groove in said piston; anda seal element disposed in said annular groove.
 12. A fluid connectionas defined in claim 11, wherein said annular groove includes a steppedbottom surface defining an annular recess within said annular groove.13. A fluid connection as defined in claim 12, wherein said at least onehole extends from a first bottom surface of said annular groove to saidaperture in said piston.
 14. A fluid connection as defined in claim 11,wherein said seal element has a J-shaped cross-section with a baseportion, an outer leg portion and an inner leg portion.
 15. A fluidconnection as defined in claim 11, wherein said seal element and saidgroove define a cavity between said seal element and said outer surfaceof said piston.
 16. A fluid connection as defined in claim 1, furthercomprising: a seal element disposed between said piston and saidpassage, said seal element defining an interior cavity; at least onehole extending radially through said piston, said hole fluidlyconnecting said aperture in said piston to said interior cavity in saidseal element.
 17. A fluid connection comprised of: a first fittinghaving a body with a first end and a second end; a passage extendingthrough said body from said first end to said second end; a bracketmounted to said second end of said body, said bracket defining a spaceadjacent said second end; mounting means for mounting said first end toa stationary fluid inlet line; a piston movable within said passage,said piston having an outer surface, an inlet side facing said first endof said body and an outlet side facing said second end of said body; anaperture through said piston fluidly connecting said inlet side of saidpiston to said outlet side of said piston; and a second fitting having afluid opening therethrough, said second fitting being dimensioned to beslidably received within said space adjacent said second end of saidfitting, wherein said piston is movable into engagement with said secondfitting with said aperture in said piston communicating with the fluidopening in said second fitting.
 18. A fluid connection as defined inclaim 17, wherein said piston is generally cup-shaped and has a bottomwall defining a surface and an annular, cylindrical side wall extendingtherefrom.
 19. A fluid connection as defined in claim 18, wherein saidfirst end of said body includes a flange for mounting said body to saidfluid inlet line.
 20. A fluid connection as defined in claim 19, whereinsaid first end of said body is attached to said fluid inlet line by acollar clamp.
 21. A fluid connection as defined in claim 20, whereinsaid piston forms a seal against a surface on said second fitting.
 22. Afluid connection as defined in claim 21, wherein said surface on saidsecond fitting is a planar surface.
 23. A fluid connection as defined inclaim 17, wherein said bracket is a generally C-shaped plate defining agenerally rectangular space, and said second fitting is a flangedcomponent dimensioned to be slidably received in said rectangular space.24. A fluid connection as defined in claim 23, wherein said secondfitting includes a cylindrical body having an annular outwardlyextending flange at one end of said cylindrical body, said flange havinga planar end surface.
 25. A fluid connection as defined in claim 24,wherein said aperture in said piston is dimensioned such that the totalcross-sectional area of said aperture is less than the cross-sectionalarea of said stationary fluid inlet line.
 26. A fluid connection asdefined in claim 17, further comprising: an annular groove formed insaid outer surface of said piston; at least one hole extending radiallythrough said piston, said hole fluidly connecting said aperture in saidpiston to said annular groove in said piston; and a seal elementdisposed in said annular groove.
 27. A fluid connection as defined inclaim 26, wherein said annular groove includes a stepped bottom surfacedefining an annular recess within said annular groove.
 28. A fluidconnection as defined in claim 27, wherein said at least one holeextends from a first bottom surface of said annular groove to saidaperture in said piston.
 29. A fluid connection as defined in claim 26,wherein said seal element has a J-shaped cross-section with a baseportion, an outer leg portion and an inner leg portion.
 30. A fluidconnection as defined in claim 26, wherein said seal element and saidgroove define a cavity between said seal element and said outer surfaceof said piston.
 31. A fluid connection as defined in claim 17, furthercomprising: a seal element disposed between said piston and saidpassage, said seal element defining an interior cavity; at least onehole extending radially through said piston, said hole fluidlyconnecting said aperture in said piston to said interior cavity in saidseal element.